CVE-2018-20721 — URI_FUNC() in UriParse

URI_FUNC() in UriParse.c in uriparser before 0.9.1 has an out-of-bounds read (in uriParse*Ex* functions) for an incomplete URI with an IPv6 address containing an embedded IPv4 address, such as a "//[::44.1" address.

01What is this vulnerability?

URI_FUNC() in UriParse.c in uriparser before 0.9.1 has an out-of-bounds read (in uriParse*Ex* functions) for an incomplete URI with an IPv6 address containing an embedded IPv4 address, such as a "//[::44.1" address.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2019-01-16T14:00:00.000Z
• Last modified: 2024-08-05T12:12:28.191Z

09References

• lists.debian.org — https://lists.debian.org/debian-lts-announce/2019/02/msg00028.html
• github.com — https://github.com/uriparser/uriparser/commit/cef25028de5ff872c2e1f0a6c562eb3ea9…
• github.com — https://github.com/uriparser/uriparser/blob/master/ChangeLog
• lists.debian.org — https://lists.debian.org/debian-lts-announce/2021/11/msg00029.html